What Does P1197 Mean?
The oxygen sensor heater circuit for Bank 2 Sensor 1 (upstream sensor, engine bank opposite cylinder #1) has an electrical malfunction. This affects sensor warm-up on the second bank of a V-engine.
Common Causes
40%
Failed Bank 2 Sensor 1 oxygen sensor with heater circuit fault
30%
Open or short circuit in Bank 2 oxygen sensor heater wiring
15%
Blown heater fuse or failed heater relay
10%
Corroded connector terminals or damaged connector housing
5%
ECU heater driver circuit malfunction
Diagnostic Steps
1
Step 1: Verify heater fuse and relay condition for Bank 2 circuit
2
Step 2: Disconnect Bank 2 Sensor 1 connector and measure heater resistance at sensor (should be 3-30 ohms typically)
3
Step 3: Check for battery voltage at heater power wire with ignition on
4
Step 4: Test ground circuit continuity from sensor to ECU or chassis ground
5
Step 5: Compare readings with Bank 1 sensor to identify if issue is sensor-specific or system-wide
Estimated Repair Cost
$120 - $450
Parts + labor, varies by vehicle and location
The oxygen sensor heater circuit for Bank 2 Sensor 1 (upstream sensor, engine bank opposite cylinder #1) has an electrical malfunction. This affects sensor warm-up on the second bank of a V-engine.
The most common cause of P1197 (O2 Sensor Heater Circ.,Bank2-Sensor1 Electrical Malfunction) is: Failed Bank 2 Sensor 1 oxygen sensor with heater circuit fault
Typical repair costs for P1197 range from $120 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive but Bank 2 fuel control will be compromised until sensor warms up, causing increased emissions and possible rough running.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1197 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System / Emissions Control
Difficulty
Type
Manufacturer
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